1. Technical Field
The present invention relates generally to the communication systems; and more particularly to a wired communication system facilitating both voice and data communications, the wired communication system employing an (asynchronous transfer mode) ATM network for a portion of its switching path.
2. Related Art
Wired communication systems that facilitate voice communications are well known in the art. Further, enterprise based wired communication systems are also well known in the art. In such enterprise communication systems, an organization purchases or rents its own switching equipment to facilitate voice communications within the organization. In such systems, the user typically purchases a local switch referred to as a private branch exchange (PBX) to provide local switching for end point devices, such as telephones, as well as to provide an interface to the Public Switched Telephone Network (PSTN).
In its operation, the PBX sets up and routes voice communications between end point devices that are located within the organization. Further, the PBX also sets up communications between the end point devices it serves and distant endpoint device connected to the PBX by an enterprise network or the PSTN. In some enterprise communication systems, peripheral equipment is also installed to service endpoint devices which provide interfaces to a number of endpoint devices. For example, a university or large corporation may have a centrally located PBX and have peripheral equipment located at each physical location where end point devices reside.
The peripheral equipment is linked to the PBX via a dedicated time switched line such as a T1 line. In such systems, the PBX typically sets up all calls between the end point devices. Further, in some systems, the PBX routes all calls within the enterprise communication system. Thus, in some systems, the peripheral equipment acts merely to package calls onto and from the lines linking the PBX to the peripheral equipment. Such packaging of calls, which may be coded in a pulse code modulated (PCM) format, is typically accomplished via a time division multiplexing (TDM) scheme.
As organizations expand at their physical locations, the number of endpoint devices increases, and additional peripheral equipment must be installed to service the additional end point devices. Additional dedicated lines must also be installed from the new peripheral equipment to the PBX. The cost of these lines is often substantial since the lines must typically be leased from a local phone company or be completed with dedicated hardware connections that are expensive to install.
In many organizations, local area networks, wide area networks, and global area networks service data transfer among computer systems operating within the organization. An example of such a network is an asynchronous transfer mode (ATM) network. An ATM network is packet based and is typically a dedicated network having its own set of switches, routers, repeaters and other equipment which is interconnected by dedicated communication lines. Network computers connect either directly to the ATM network or via a bridge between another type of computer network, e.g. an Ethernet network, and the ATM network. Operation of the ATM network is incompatible with the time switched voice communication network since the ATM network is a packet based network and the voice communications network operates in a time switched fashion. Thus, when an organization expands, the ATM network must be expanded in addition to expansion of the voice network to facilitate additional computer resources.
Thus, there is a need in the art for a system that combines resources required for voice communications and data transfer so that required expansions for the transmission of data between computers and required expansions for voice communications in an enterprise type system may combine resources.